The lowest gain for LM3886 stability recommended is 10. Since we use it as a difference amplifier, it actually doubles the signal and as a result we get gain of 20V/V for LM3886 that is minimum recommended.
Setting the gain for the first stage to 1.1 gives overall gain of 22
Setting the gain for the first stage to 1.1 gives overall gain of 22
Coming back to this discussion because now I have a different perspective on my paralleled LM3886 build.
I have built modular paralleled TDA7293 amp and it sounds so much better than LM3886!
I have yet to discover the issue with the LM3886x2 build.
but I will be trying the following:
removing the cap between inv and non-inv inputs of the chip,
removing all stability components by the datasheet,
increasing the gain
or maybe use servo (will take much longer with the whole board redesign)
It is little puzzling to me that even though THD measurements were fine, there is some kind of issue still present.
Meaning that I just did not measure what was needed to be measured.
But I could tell the difference while listening and comparing both amps.
I have built modular paralleled TDA7293 amp and it sounds so much better than LM3886!
I have yet to discover the issue with the LM3886x2 build.
but I will be trying the following:
removing the cap between inv and non-inv inputs of the chip,
removing all stability components by the datasheet,
increasing the gain
or maybe use servo (will take much longer with the whole board redesign)
It is little puzzling to me that even though THD measurements were fine, there is some kind of issue still present.
Meaning that I just did not measure what was needed to be measured.
But I could tell the difference while listening and comparing both amps.
